1. Field of the Invention
The present invention relates to a glass run adapted to be attached to an inner periphery of a door frame of an automobile door for guiding a door glass as it is raised and lowered.
2. Description of Related Art
As shown in FIG. 1, a glass run 10 is attached to an inner periphery of a door frame 12 of an automobile door 14 for guiding a door glass 16 as it is raised and lowered. An entire part of the conventional glass run 10 is shown in FIG. 2, and the cross-section of the conventional glass run 10 attached to straight parts 10a of the door frame 12 is shown in FIG. 3 and FIG. 4.
As shown in FIG. 1, conventionally, the glass run 10 is attached within a channel of the door frame 12 to guide the door glass 16 as it is raised and lowered, and provide a seal between the door glass 16 and the door frame 12. In addition, as shown in FIG. 2, the conventional glass run 10 includes an upper side part 10c for attachment to an upper side of the door frame 12, a rear vertical side part 10d for attachment to a rear vertical side of the door frame 12, a front vertical side part 10e for attachment to a front vertical side of the door frame 12 and corner parts 10b for connecting the upper side part 10c to the rear vertical side part 10d or the front vertical side part 10e. 
The upper side part 10c, the rear vertical side part 10d and the front vertical side part 10e define straight parts 10a formed by extrusion.
And in order to minimize a level difference between an exterior surface of the door glass 16 and an exteriori surface of the door frame 12, the exterior surface of the door glass 16 has been made approximately flush with the exterior surface of the door frame 12. As shown in FIG. 3, in a conventional flush type glass run 10 thus arranged, a side edge 18 of the door glass 16 contacts an outer seal lip 20 to provide a seal between the door glass 16 and the door frame 12. A slider 22 attached to the door glass 16 slides an interior space of the glass run 10 to guide the door glass 16.
In this case, when the door glass 16 is raised and lowered along the vertical sides of the door frame 12 with the side edge 18 of the door glass 16 contacting the outer seal lip 20, as shown by dotted lines in FIG. 3, the outer seal lip 20 reverses to project outwardly of an automobile body, thereby degrading the appearance around the outer seal lip 20.
In addition, a stress may be concentrated on a base part 24 of the outer seal lip 20 to deteriorate the durability of the glass run 10, and consequently, cracks may be generated in the outer seal lip 20.
Under such circumstance, as shown in FIG. 4, in order to improve both the durability and the sealing properties of the outer seal lip 20, another conventional glass run 30 is arranged to have an outer seal lip 32 and an outer cover lip 34, each extending from an outer side wall 36. And a first inner seal lip 38 and a second inner seal lip 40, each extending from an inner side wall 42, are provided to seal the slider 22 attached to the door glass 16 (see Japanese patent application laid-open No, 2006-56472, for example.)
In this case, four seal Ups are provided for sealing so that, in order to adequately bring the slider 6 attached to the door glass 16 into contact with the four seal lips, the glass run 30 has been required to be assembled with high precision, and the outer cover lip 34 for covering the door glass 16 becomes long, thereby degrading the appearance quality therearound.